Rocket fuse



Jam 20, 1959 Y J. G. vlLLEPlGUE ,2,869,465

ROCKET FUSE 7 Sheets-Sheet 1 S3 NN kbMWNkQMAmY m. Mmmm \Nm.

Filed April 26, 1954 Jall- 20, 1959 J. G. VILLEPIGUE 2,369,465 Y ROCKET FUSE Filed April 26, 1954 7 Sheets-Sheet 2 Jan- 20 1959 .1. G. vlLLEPlGUE 2,869,465

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Jan. 20, 1959 J. G. VILLEPIGUE 2,869,465

ROCKET FUSE Filed April 2e, 1954 '7 sheets-sheet `4 ROCKET FUSE '7 Sheets-Sheet 5 Filed April 26, 1954 Jan. 20, 1959 J.,G. VILLEPIGUE 2,869,465

' ROCKET FUSE Filed April 26, 1954 7 sheets-sheet e Jam 20, 1959 J. G. VILLEPIGUE 2,869,465

ROCKET FUSE Filed April 26, 1954 Y 7 Sheets-Sheet '7 ROCKEI` FUSE Julius G. Villepigne, Inglewood, Calif., assiguor to orthrop Aircraft, Inc., Hawthorne, Calif., a corporation of California Application April 26, 1954, Serial No. 425,596 11 claims. (ci. 1oz-70.2)

The present invention relates generally to detonator fuses and the like, and more particularly to a fuse which lis highly eliicient in rockets.

Shocks of various kinds, and static electrical charges, Y

which can result from a variety of causes during the handling of rockets, are an ever present danger.

Furthermore, serious consideration must be given to the possibility of battle damage to the airplane electrical system and its effect of the ring system of the rockets.

To these and other ends, it is among the objects of the present invention:

To provide an improved fuse for rockets.

To provide an improved fuse for rockets which is entirely contained within the rocket itself.

To provide a self-contained fuse for rockets which is independent of an outside source of power for the operation thereof.

To provide a composite fuse mechanism capable of performing the following functions in a missile:

(l) Ignition of the missile propulsion charge.

(2) Arming of the missile warhead fuse.

(3) Ignition of the missile warhead.

(4) Destruction of the missile after a pre-established time interval, if the missile has not struck a target.

To provide a fuse for a missile, such as a rocket, which will not arm the rocket warhead until a predetermined sequence of events takes place.

To provide means for preventing detonation of the warhead of a missile upon mishandling or accidental dropping thereof.

To provide la missile fuse mechanism which will automatically detonate the missile warhead if the missile has not struck a target within a predetermined period of time after missile launching, and after a prespecifed period of acceleration.

And to provide a rocket having a self-contained fus mechanism, and power supply therefor, lwhich is entirely independent of any power source exterior of the rocket.

Although the fuse of the present invention is for use in standard type rockets including those of the iin stabilized class, it has been proposed to spin stabilize rockets, and the copending patent applications, Serial Numbers 425,594, led April 26, 1954, by Edgar Schmued et al., 425,595, filed April 26, 1954, by Edgar Schmued, and 467,332, iled November 8, 1954, by John H. Bach et al., now U. S. Patent 2,792,758, describe,

n 2,869,465 Patented Jan. 20,1959

show, and claim means and methods for rocket spin stabilization.

To this end, the particular embodiment of the rocket fuse disclosed for illustration in the present application is adapted for use in a spin stabilized rocket, and therefore among the objects of this invention, in addition to the above cited objects, are:

To provide a fuse, one embodiment of which is adapted for a spin launched rocket wherein the initial spin given the rocket in the launching bed is used to ignite the rocket propellant.

To provide a fuse for a spin launched rocket wherein spinning, and spinning only, of the rocket initiates and permits ignition of the rocket propellant. f

To provide fuse for a rocket wherein the rocket propulsion charge is ignited only when the rocket is rapidly rotated or spun about its longitudinal axis, and in which the possibility of accidental ignition of the rocket propellant, such as might occur when the rocket is inadvertently dropped or otherwise subjected to other type of shock, is substantially eliminated.

And to provide a finless rocket having a self-contained fuse mechanism, and power supply therefor, which is entirely independent of any power source exterior of the rocket body.

Briefly, the fuse of the present invention, inthe particular embodiment chosen for illustration herein, comprises rocket warhead larming and detonating means responsive only to acceleration force, and a power source therefor; rocket destruction means responsive only yto deceleration force, and a power source therefor; and rocket propellant charge ignition means which is responsive only to centrifugal force, and a power source therefor. The fuse power source is preferably common to all of the means, and each means is coactive with another to initiate operation thereof so that a predetermined sequence of events is established for complete operation of the fuse. All of the fuse means, and the common power source therefor, are preferably contained in a single compact package for incorporation into the rocket body; the fuse being entirely independent of any exterior mechanism or power supply.

Still other advantages and objects of the invention will become apparent by perusal of the ensuing description of the appended drawings which show the invention; clearly illustrating to those skilled in the art the method of the invention together with several preferred apparatus embodiments which practice the method.

In the drawings:

Figure l is a perspective view showing the present invention in use in a tail turret of an airplane.

Figure 2 is a longitudinal sectional View of a rocket in position in a launching bed.

Figure 3 is a simplified circuit diagram of the ignition and fusing device carried by the rocket of Figure 2.

Figure 4 is a view partly in section and partly in elevation taken as indicated by line 4 4 in Figure 2.

Figure 5 is a cross-sectional view of the rocket of Figure 2 taken as indicated by line 5 5 therein.

Figure 6 is a perspective view of the rear of a bank of four launching tubes showing one type of rocket release mechanism.

Figure 7 is a diagrammatic side view of the rear of a launching tube showing how a spin spring is wound.

Figure 8 is a View partly in section and partly in elevation of a release mechanism disconnect.

Figure 9 is an enlarged longitudinal sectional view of the rear of a launching bed with a rocket in place ready for launching.

Figure 10 is a cross-sectional view taken as indicated by the line 10710 in Figure 9.

Figure 11 is a cross-sectional view taken as indicated by line 11--11 in Figure 9. l

Figure 12 is an explodedv perspective view of the ignition and fusing device .and self destructor carried by the rocketmof Figure 2.

Figure 12a is a longitudinal vsectional view of the same device as shown in Figure 12. Y v

Figure 13 is an exploded perspective view of a spinner sleeve and spring, and the rear end of a rocket showing the coupling means.

Figure 14 is a longitudinal sectional View of a rocket launcher in which initialvspin of the rocket is imparted by one form of solid fuel turbine.

Figure 15 is a cross-sectional view taken as indicated by the line 15--15 in Figure 14. i

Figure -16 is an enlarged view partly in section and partly in elevation taken Yas indicated by the line 16-16 in Figure 15.

Figure 17 is a top plan view showing how launchers of the type shown in Figure 14 can be stacked.V

Figure 18 is a longitudinal sectional view of the rear portion of a rocket launcher using another form of solid fuel turbine to spin the rocket.

Figure 19 is a perspective view of the forward end of the turbine shown in Figure 18.

Figure 20 is a perspective View of the rearward or dislcharge end of the turbine shown vin FigureV 18.

One particular and preferred form of rocket suitable for use in the practice of the present invention will first be described.

Referring to Figures 2, 3, 4, 5, l2 and 12a, and particularly to Figure 2, a rocket 1 0 comprises a pointed forward casing 11 containing an explosive 12, and an aft casing 14 .containing a hollow propellent charge 15. The `af'tcasing 14 is of thinner wall construction than is the forward casing 11 and is bonded to a securing ring 16, which Yis in turn threaded onto the rear portion of the forward casingV 11', to form an elongated rocket body.

Clamped between a flange 17 on the securing ring 16 and the rear edge of the forward casing 11, is a circumferential double wall Bange 19 extended laterally yfrom a f use and-igniter assembly 20. A fuse housing 21 is preferably metallic and has one ange portion 22 formed lon the rear end thereof. The outer portion of a rear wall or cap 24 (Figure 12a) .overlies the flange portion 22 to complete the iange 19. 'lhe cap 24 serves to close the rear end of the housing 20. The fuse and igniter assembly 20 thus forms a wall separating the explosive 1 2 in the warhead from the propellent charge 15.

Within the housing 21 and generally centrally positioned therein, there is mounted an electric battery 25. This battery, as best shown in Figure 12a, hasa dual cell arrangement composed vof two cells, a front dry cell 26 and a rear dry cell 27, these cells having a common positive terminal 29 and two separated negative terminals 30 and 31. The common positive terminal 29 is the metal cylindrical case of the battery, and is grounded through battery ring 34 to the fuse housing 21; the other two terminals and 31 being vformed as end caps at each end of terminal case 29 and insulated therefrom by sealing insulators 35 The construction of the cells 26 and 27 is conventional, with the exception that a depolarizer mass 36 is common to both cells. The front cell 26 is larger than the rear cell 27, for reasons later to bediscussed.

The housing 21 constitutes a 4positively poled ground for the circuits energized by the battery 25.

Referring next to both Figures 12 and 12a, the terminal 31 of the above mentioned negative terminals of the battery25 extends rearwardly from the central portion of the battery in the form o f aboss 37. Transversely positioned within the housing 21 and abutting the rear terminal 31 is a relatively thin insulating disc 39 having a central opening'therein through which the boss 37 extends rearwardly. At the-rear'of the disc 39 and extending to the rear cap 24 of the housing 21 is an insulating heat'resisting'tefminal block `40"'Then face ofthe block 40 adjacent the disc 39 is relieved to form a fiat, transverse chamber 41 in which switch means, to be described hereinafter, is mounted. The unrelieved portions of the forward face of the block 4 0 abut the disc 39 as best shown in Figure 4; these unrelieved portions consisting of an inner arcuate portion 42 and a larger side portion 44 having an outer arcuate portion 45 extending therefrom. Transverse chamber 41 contains a centrifugal switch assembly C next tobe described.

Movably disposed within the chamber 41 shown in Fig'- ures 4 and 12 is a rst switch member S consisting of a heavy wire formed into a ring 46 surrounding the rear terminal boss 37 of cell 27 and also embracing the inner arcuate portion 42 of the terminal block 40. Formed on the ring 46 is a contact member in the form of an inner point 47 directed inwardly toward the rear terminal boss 37 and disposed on the opposite side of the terminal boss 37 from the inner arcuate wall 42. The wire of the ring 46 then is continued radially as a doubled portion 49 opposite the inner point 47. A weight 50 is mounted on doubled portion 49. One end of the wire is extended rearwardly from the doubled portion 49 to form a resilient mounting arm 51, which extends circumfereutially partially around the ring 46 and then turns rearwardly and enters into the terminal block 40, as best shown in Figure 12.V This latter portion of the switch member S then turns within the terminal block 40 toward the center of the block and finally turns again to the rear and emerges rearwardly from the block 40 as a .first primer terminal 52 into'a primer chamber 54 formed in a rearward primer housing 55 in the end cap 24 (Figure 12a).

In practice it is preferred to mold the switch member S, just described, into the block 40 so that it is firmly positioned thereby. Any suitable configuration of the switch member S can be employed as long as it is mounted -in the chamber41 so as to permit the inner point 47 to be brought into engagement with the terminal boss 37 of the cell 27, and is so designed that the center of mass of the aggregate movable portion of the switch member is on the side of the terminal opposite the inner point 47, so that centrifugal force resulting from spinning of the rocket will force the switch member S inwardly as shown in Figures l2 and 12a, thereby bringing the inner point 47 into electrical contact vwith the ybattery terminal boss 37. The resiliency of the arm 51 permits such motion of the ring 46 and also Ibiases the inner point 47 away from the boss 37, as shown in Figure 12a when the rocket is at rest.

While the single switch member S, described immediately above, willV make electrical contact with the terminal boss 37 upon spinning of the rocket, such contact might also be eifected if the rocket were to be dropped or subjected to sudden shock which would cause an accelera` tion of the rocket outwardly with reference to the orientation of Figure 12a. Such acceleration of the housing might well cause a relative upward movement of the ring 46 and bring the inner point 47 into engagement with the boss 37, thereby closing any circuit inv which the switch member S is connected. Such dropping of the rocket might thus cause an unwanted ignition of the rocket propellant. to make certain that the rocket propellant will be ignited only when the rocket is spun, and not when it is subjected Y to accidental forces while being handled.

Such means is provided in the form of a second switch member SS comprising a second resilient arm 56. One end ofV the second arm 56 has an outwardly directed contact portion in theform of an v outer point 57 positioned radially outward from the'inner point 47 on the ring '46, and on the oppositeside of the'outer arcuate wall portion 45 of the terminal block 4 0.` T he end of the second resilient arm 56 which carried the-outer point 57 is free to `move in chamber 41; and this arm extends circum- Means have therefore been provided ferentially partially around 'the arcuate wall portion 45, and the ring 46 and then is bent rearwardly to enter the terminal block 40, as best shown in Figure 12, in a manner similar to the mounting of the first switch member S. The second switch member SS then continues through the terminal block ttl and emerges rearwardly into the primer chamber 54 in the primer housing 55 .as a second primer terminal 59.

In the primer chamber 5a, between the two primer terminals 52 and 59, is electrically connected a filament 60 which is adapted to be heated when an electric current is sent therethrough from cell 27. On and around the lament 60 is placed an igniting pellet 61, and a mass of primer material 62 fills the remainder of primer housing 55. 1n the rear wall of ythe primer housing 55 is a passageway 64 which communicates between the primer material 62 and the hollow interior of the propellent charge 15. The passageway 64 is normally closed with a frangible seal 65, best shown in Figure 12a.

The operation of the propellent charge igniter described above is substantially as follows: The rocket is first caused to spin within its launching bed, which may be a conventional launching tube. Such spinning can be effected by any suitable means, ibut preferably by devices herein later described.

The centrifugal force resulting from the spinning of the rocket causes the ring 46 and weight Si) of switch member S to swing upwardly (as the drawing is oriented in Figure 4) because that portion of the switch member S above the spin axis 4of the rocket is of greater mass than is the portion below. This brings the inner contact point 47 into electrical engagement with a terminal boss 37 of cell 27. Simultaneously, `centrifugal force also swings the second arm 56 outwardly (downwardly as oriented in Figure 4) and brings outer point 57 into engagement with the inner face `of the fuse housing 2l. These portions of members S and SS are shown in dotted lines D in Figure 4.

Closing of both of these switch member contacts closes a circuit which can be traced as seen in Figures l2 and 12a and in the circuit diagram of Figure 3 as follows: From the rear cell 27 of the battery 25 to the rear negative terminal 31, through boss 37, inner contact point 47, ring 46, arm 51, first primer terminal 52, through the tilament, then to the second primer terminal 59, second resilient arm S6, outer contact point 57, housing 21, battery ring 34, and then thence to the positive grounded terminal of the dual battery 25 and cell 27 in particular. The potential of the rear cell 27 is thus applied across the primer filament 69, heating it to ignite the primer peliet 61 which in turn ignites primer material 62. The ilame from the priming material 62 fractures frangible seal 65 and enters the inside of the propellent charge 15, igniting this charge to start rocket thrust.

It is to be noted at this point that the circuit under `the control of the centrifugal switch is energized solely from .the rear cell 27 of battery 25. Consequently, even if the two primer firing terminals 52 and 59 should be shorted after primer explosion, thereby rendering the rear cell useless, such shorting will not affect the operation of the forward cell 26, which is to be used at a later time in conjunction with the amiing and detonation of the warhead 12 of the rocket.

The remainder of the mechanism in housing 2l will next be described, also best shown in Figures l2 and 12a.

In the forward end of housing 21, between the front wall 71 thereof and the forward terminal 36 of the dual battery 25 and cell 26 in particular, is located the fuse or detonation mechanism for the rocket warhead. Abutting the forward end of cell 26 is a relatively thick insulation disc 72 having an axial passage or opening 74 therethrough communicating with the forward negative terminal 30 of the cell 26. Axially mounted within the forward end of fuse housing 21 and opening 74 is an acceleration pin 75 of conducting material. The pin 75 ismovable in the opening 74, sothat thefpointedgrear end 76 of the pin 75 can be brought into contact with the forward battery terminal 30. The pin is also provided with an annular shoulder 77 serving as a forward stop for a rear helical compression spring 79 disposed around the pin 75. The rear end of the rear spring 79 abuts an annular inwardly directed shoulder S0 formed by reducing the diameter of the `opening 74 in disc 72 just forward of the battery terminal Sti.

The forward end of the pin 75 is slidably engaged by three inwardly and rearwardly extending radial resilient fingers 81 forming part of a conducting contact disc 82. A second, and weaker front compression spring 84, extends around pin 75 from the shoulder 77 to the contact lingers 81. The contact disc 82 is secured to the front surface of the inner convolution of an electrical resistance heater 85 mounted on a bimetallic disc 86. The bimetallic disc 86 is composed of two laminae of different metals bonded together so that as the disc 86 is heated it tends to distort. A layer of electrical insulation 86a is -interposed between the heater 85 and the bimetallic disc 86.A This insulation 96a, while preventing electrical contact between the heater 85 and the bimetallic disc S6, still permits the transmission of heat from the heater tothe disc.

At its periphery the disc 86 is clamped longitudinally between a forward insulating member 87 and an insulated spacer ring 89 disposed rearwardly of the disc.

Referring to Figure 12, it will be seen that the bimetallic disc S6 contains a pair of spiral slots 90 which split the disc 86 into an outer ring portion 91, which is clamped between the members 86 and 89; an inner ring portion 92; and a pair of arcuate arms 94, each of which connects the outer ring portion 91 with the inner ring portion 92. With the disc 86 thus divided by the slots 90, heating of the disc 86 by the heater 85 results principally in a longitudinal bending of the two arms 94 from the solid line position shown in Figure 12a to the dotted line position, where the inner ring portion 92 has been translated rearwardly along the axis of the housing 21 as shown in Figure 12a.

The heater 85, bonded to the bimetallic disc 86, has substantially the same configuration as the disc 86, as shown in Figure 12. Like the disc 86, thev heater 85 is divided into an inner ring 95, and a pair of arcuate arms 96 which communicate with the inner ring portion 95 on opposite sides thereof and extend spirally around the inner ring portion and having extensions which extend outwardly to contact the exterior of the housing 21. In this manner the heater 85 can be connected electrically to have two parallel paths which are connected across the housing 21 and the contact disc 82 secured to the inner ring portion 95 of the heater 85.

Mounted on the rear face of the inner ring portion 92 of the bimetallic disc 86 in electrical contact therewith are a pair of rearwardly extending electrical contact points 97. An intermediate contact means in the form of a conducting disc 99 is disposed just rearwardly of the spacer ring 89 and is clamped transversely in the housing 21 between the spacer ring 89 and a separator ring but is not in contact with housing 21. The conducting disc 99 has substantially the same spiral configuration as the bimetallic disc 86.

Energization of the heater 85 causes the temperature ofthe bimetallic disc S6 to steadily increase and thus steadily translate the contact points 97 rearwardly until they` engage the inner ring portion 98 of the intermediate conducting disc 99. Further'heating of the bimetallic disc 86 causes the points 97 to move still further rearwardly, pushing the inner portion 9S of the intermediate conducting disc 99 rearwardly.

An impact actuator is provided in the form of an impact disc 101 positioned at the rear of the intermediate conducting disc 99 and having substantially the same spiral conguration as the discs 86 and 99. `The outer ring portion of the impact disc 101 is clamped between the separator ring 100 and the thick insulation disc 72 but is not in contact with housing 21. The inner ring portion of the impact disc 101 is turned rearwardly to form a cylindrical ange 102 within which is fitted a contact cylinder 104, the forwardredge of which is serrated to insure a good electrical contact against the inner ring portion of the intermediate conducting disc 99, when the two members are brought into engagement with each other. An annular groove 105 is formed in the forward face of the thick insulation disc 72 in order to'accommodate flange 102 and contact cylinder 104.

A back-up shoulder 106 is formed on the spacer ring 89 extending inwardly far enough to overlie the outer edge of the inner ring portion of the intermediate conducting disc 99 without interfering with the rearward motion of the contact points 97. This back-up shoulder 106 serves to prevent conducting disc 99 from vibrating, and also prevents the inner ring portion of conducting disc 99 from being pushed forward by the contact cylinder 104 in the event the rocket should be dropped during loading.

A shock pad 107 is placed between the front wall 71 of the housing 21 and the forward insulating member 87, so that the several parts of the fuse mechanism are firmly held between the forward terminal 30 of the cell 26 vand the front wall 71 of the housing 21.

Around the outer periphery of the thick insulating disc 72 is an annular groove 109. Extending inwardly from the groove at one point is a radial bore 110 in which is located an electrically fired detonator pellet 111, mounted on a detonator lament 112 connected between the forward battery terminal 30 and the outer ring portion of the impact disc 101 by means of conductors 114. The groove 109 and a portion of the passage 110 are filled with an explosive primer 115. The groove 109 communicates with the explosive 12 in the warhead by means of a plurality of holes 116 spaced circumferentially around the housing 21. The holes 116 are closed by a burnable sealant 117.

The impact disc 101 is made of relatively springy material, so that when the rocket strikes a target, the central portion of the disc 101, including the contact cylinder 104, is impelled forward relative to the other part of the mechanism, so as to come into electrical contact with the intermediate conducting disc 99. The disc 99 is restrainedtagainst forward movement by the back-up shoulder 106 and disc 86, on the other hand, is relatively sti, so as to be substantially unaffected by longitudinal accelerations and decelerations of the rocket. All three discs, S6, 99, and 101, are of conducting material as is the Contact disc 82, fingers S1, and the acceleration pin 75. Each of the several parts ofthe detonation mechanism is constructed with substantial polar symmetry as reference to Figures 12 and 12a will indicate. In this way, internal stresses resulting from the centrifugal forces of the spinning of the rocket are minimized.

Operation of the warhead detonation mechanism is substantially as follows: As soon as the rocket propellent charge is ignited by the centrifugal switch assembly C, forward acceleration is imparted to the rocket, which exists for the duration of the burning of the propellent charge 15. This forward acceleration causes a rearward reaction force to act upon the acceleration .pin 75 forcing it rearwardly into engagement with the front battery terminal against the bias of the tirst compression spring 79. A circuit is thus completed from the forward negative terminal 30 of cell 27' through the pin "i5, fingers 81, contact disc 82, to the heater S5. As the outer portions of the heater 85 are grounded to the case 21, the circuit then returns to the sheath of the battery 25 which is the positive terminal of forward cell 26. The heater 85 thus will be energized to heat the bimetallic dise 86. As the temperature of the disc 86 rises, the inner ring portion 92 thereof translates rearwardly.

If the rocket should be suddenly decelerated before it had reached a safe distance from the launchenthe Contact cylinder 104 would of course be impelled forwardly into engagement with the intermediate conduct ing disc 99. However, this period would not have beenl sufficient to permit the heater 85V to cause the birnetallic disc 86 to move the contact points 97 into contact with the intermediate conducting disc 99. Thus the detonation circuit would not be completed and the warhead will not explode.

However, as the contact points 97 continue to move reawardly under continued heating of the bimetallic disc S6, by the heater 85, these contacts 97 `come into engagement with the intermediate conducting disc 99. At this moment the fuse becomes armed, that is, operation of the contact cylinder 104 can now detonate the rocket, i. e., the circuit is now ready to be completed by forward movement of the Contact cylinder 104.

ln the meantime, however, and perhaps before the contact points 97 have kengaged the intermediate disc 99, the propellent charge 15 may have burned out, so that the rocket starts to slowly decelerate. Under this condition, the acceleration pin would tend to move forwardly under the bias of the first compression spring 79. However, under the rearward movement of thc bimetallic disc, heater fingers 81 have by now placed the front spring 84 under compression and this force is transmitted to the pin 75 through its shoulder 77, thus keeping the pin 75 pressed against the terminal 30 against the counter bias of first spring 79. Thus the circuit to the heater 85 is maintained closed and the bimetallic disc 86 continues to be heated.

A predetermined time after the rocket has been armed it may he desirable that it should be automatically detonated if it has not by that time struck a target. This detonation is effected by the contact points 97 continuing to move rearwardly under continued heating by the heater 85; the points now pushing the inner portion ofthe intermediate conducting disc 99 tothe rear. If the heating is continued long enough, the points 9'! will eventually push the inner portion 98 of intermediate conducting disc 99 into engagement with the contact cylinder 104, thus completing the detonation circuit and exploding the rocket.

in normal operation, however, the rocket strikes a target some time after being armed and before being automatically exploded. Assume that by heater operation, the contact points 97 are in contact with the intermediate conducting disc 99. Striking of the target impcls the contact cylinder 104 forward, without causing a corresponding movementof the discs 86 and 99, because of the difference of stiffness of these latter parts. Thus, the contact cylinder 104 is brought into engagement with the intermediate conducting disc 99, and a detonation circuit is completed. This detonation circuit can be traced from the sheath 29 of the cell 26 through the Contact ring 34 and to the housing 21, through the bitnetallc disc 86, contact points 97, intermediate conducting disc 99, contact cylinder 104, impact disc 101, conductor 114, filament 112 on which detonator pellet 111 is mounted, conductor 114, to the forward negative terminal 30 of cell 26. The detonator pellet 111 ignites and this in turn ignites the primer 115. The primer then explodes outwardly, fracturing the seals 117 and detonating the explosive 12 in the warhead.

if the rocket is suddenly decelerated before being armed, the Contact cylinder 104 is prevented from pushing the intermediate disc 99 forwardly into engagement with the contact points 97, because of the presence of the backup shoulder 106, which serves as a forward stop prohibiting any forward movement of the intermediate contact disc 99. At the same time, rearward motion of the intermediate contact disc 99, more particularly the inner ring 98 thereof, is still permitted under the urge of the contact points 97.

Data on one particular type of small spin-stabilized rocket constructed in accordance with the present 1nvention are as follows:

Diameter 1.12 inches.

Total length 22.3 inches. Weight 1.7 pounds. Burning time about .4 second. End velocity about 2500 ft./sec. Warhead explosive .2 pound.

Spin spring, pre-stress in./lbs.

Spin spring, full stress 200 in./lbs.

Rocket held against forward motionl turn.

Centrifugal switch makes Contact atabout turn.

Acceleration switch makes contact at- 50 g.

Wai-head detonator contact delay about 180 millisec.

(Rocket armed at about ft. from launcher.)

Automatic rocket destruction at about 1 mile from launcher.

The rocket just described is particularly suitable for launching from a launching bed which provides an initial stabilizing spin to the rocket. This spin can be imparted to the rocket by a number of means, several of which will be described in detail herein by reference to Figures 2, 9, 13, l6 and 18. A mechanical spinner will iirst be described as best shown in Figures 2 and 9.

A rocket launcher assembly is shown comprising a launching bed in the form of a tubular smooth bore launching tube within which is disposed the rocket 1l) to be launched. `At the rear of the launching tube 125 is a heavier spring casing 126 riveted or otherwise fastened to the tube 125. Rotatably mounted within the spring casing 126, by means of a rear ball bearing 127 only, is a spinner in the form of a tubular spinner sleeve 129, the rear edge 130 of which extends to the rear end of the heavier spring casing 126.

Spinner sleeve 129 is peripherally cut away intermediate the ends thereof, and the spring casing 126 is internally cut away opposite the cutaway portion of the sleeve to form a cylindrical spring chamber 131 in which is positioned a powerful torsion spring 132.

The forward end 134 of the spring 132 contacts a iirst abutment member 135 extending inwardly from the spring casing 126. The rear end 136 of the spring 132 is bent rearwardly and contacts a second abutment member 137 extending outwardly from the sleeve 129, just forward of ball bearing 127, as best shown in Figures 9 and l1.

Means are provided for limiting the rotation of the sleeve 129 in the casing 126 to an arc of just less than 360, as best shown in Figures 9 and 10. This means comprises the above mentioned second abutment member 137 of the sleeve 129, and a pre-stress stop 139 extending radially inward from the casing 126 adjacent ball bearing 127 into the path of second abutment 137 as best shown in Figure ll. In the position shown in Figure l1, the spring 132 is pre-stressed. When the sleeve 129 is rotated clockwise (viewed from the rear as in Figure ll) slightly less than one revolution, the spring 132 is additionally stressed by being unwound. This unwinding causes the convolutions of the spring 132 to move radially outwardly. To accommodate this radial expansion of the spring 132 when wound, the chamber 131 is made radially of greater magnitude than the expanded convolutions of the spring 132. When 1.1 inch rockets are to be spun, a pre-stress of about 50 pounds on spring 132 with a final wound stress of about 200 pounds, has been found satisfactory.

The means and method of winding and releasing the sleeve will next be described in conjunction with a bank of launchers, best illustrated in Figures 6, 7 and 8.

Sleeve 129 is, as before stated, hollow, and the nterior thereof terminates rearwardly in an outwardly flaring coned surface 149. Two winding keys 141 are spaced `diametrically on this surface, extending` longi- Y sleeves 129 are then ting the spring to unwind and spin tudinally thereof. A winding tool, such as a hand crank 142 as shown in Figure 7, has a cone 144 generally tting the interior surface of sleeve 129 and is provided with key slots 145 to receive winding keys 141.

To wind the spring 132, the crank 142 is inserted into the end of a sleeve 129 and the sleeve 129 is turned clockwise (Figure 11) slightly less than 360 until the rearwardly turned end 136 of the spring contacts the stop 139 on the casing 126. A locking pin 146 is then inserted through a rocket latch spring (later described), through casing 126 and into sleeve 129, thereby holding the sleeve 129 securely in full wound-up position (see Figures 6 and' 9). These pins 146 are used only to hold the spring 132 in wound condition until a rocket releasing mechanism is attached, one form of which is best shown in Figures 6, 7 and 8.

A plurality of launching tubes 125 are mounted sideby-side on a support frame 150. The rear edge of each spring casing 126 is provided with an upper notch 151 and the rear edge of each sleeve 129 is provided with a l sleeve notch 152, these notches matching when the spin ner spring 132 is wound.

As shown in Figures 6 and 7, a control shaft 154 is mounted on hinged arms (only one being shown) to swing from a position X adjacent upper notches 151 in the spring casing 126 to a lower position Y clear of the exhaust ends of the launchers. Spaced on shaft 154 are mounted release discs 156, each having a peripheral notch 157 therein, the edges of these discs being located along the shaft to pass through notches 151 and 152 of the sleeve 129 and spring casing 126, respectively, when the latter are adjacent and matched. Peripheral notches 157 are offset angularly one from another so that at one position of the shaft a peripheral notch 157 will register with matching notches 151 and 152 of only one launching tube at a time as control shaft 154 is rotated. Shaft 154 is rotated under thecontrol of the aircraft pilot, as for example by a geared down stepper motor 159 under control of a pilots switch 16). Shaft 154 is connected and disconnected from motor 159 by a spline disconnect S as best shown in Figure 8, for example. Here the motor end of shaft 154 is provided with an external spline 166 fitting an internal spline 167 in a spring pressed sliding spline block 169, sliding on motor shaft 170.

Using any convenient means to lock the control shaft 154 in place after being connected to motor 159 and with all release discs 156 entering their respectively adjacent matching notches 151 and 152, and with no peripheral disc notches 157 registering with the matching notches 151 and 152, the locking pins 146 can be pulled and all held in wound position by the release discs 156. Thereafter, as control shaft 154 is rotated, when and as each peripheral disc notch 157 registers with the matching notches 151 and 152 of each launching tube, the related sleeve 129 is released, permitsleeve 129 on its ball bearing 127.

After all springs 132 have been wound and locked in wound condition, either by pins 146 or release discs 156, a rocket 1t? is loaded in each launching tube 125 from the forward end thereof, and are coupled inside the launching tube to the spinning means contained in that tube.

In order to impart the spin of the sleeve 129 to the rocket 16, coupling means are provided between the sleeve and rocket. This coupling means comprises an angular driving key 171 extending forwardly from the forwardv edge of the sleeve 129; and a cooperating angular key slot 172 in the rear edge of the rocket nozzle 174 as best shown in Figure 13..

Around the outside of the rocket 10 in the outer surface of the rocket nozzle 174 is a circumferential camming groove 175 disposed forwardly of the recess 172, and extending almost 360 around the nozzle 174 as best shown in Figure l0.

Groove 175 has 'a maximum depth at one predet'er- 11 mined point P, the bottom of the groove 175 thenhaving a gradually increasing radius as it extends around the nozzle 174 until the groove ends just prior to point P, leaving an ungrooved yperipheral portion 176 on the nozzle.

Riding in the groove 175, so as normally to restrain the rocket 1t) against a forward axial movement in the launching tube 125 while still permitting rotation or spinning thereof, is a hold pin 177. In and out radial movement of the hold pin 177 is provided for by mounting the pin 177 in a pin bore 179 in the launcher parts 125 and 126, so that the pin 177 is moved outwardly from the groove 175 when it rides up on the lower surface of this groove. The hold pin 177 is normally biased inwardly into engagement with the groove 175 by a leaf spring 181B secured to the outer end of the pin 177 at M, this spring being secured to the outer surface of the housing 126 at N.

It will be noted that a forward face 181 of the hold pin 177 is made sloping, and that the forward face 182 or side of the groove 175 is correspondingly sloped to t the pin slope. The sloping face 181 of the pin 177 permits the pin 177 to be pushed or cammed outwardly as the rocket is shoved into the launching tube 125 from the forward or muzzle end thereof.

lt will further be noted, in Figure 13, that the ungrooved portion 176 of the rocket nozzle 174 is aligned longitudinally with the driving key slot 172 which is engaged by the driving key 171. By proper proportioning of these parts it is possible to make the weight removed by forming the recess 172 balance the unbalance created by unequal circumferential metal removal to form the camming groove 175, and thus retain rotational balance of the rocket nozzle, which balance is important when the rocket is launched in spinning condition.

Camming groove 175 is not strictly annular, but is slightly spiraied around nozzle 174 so that when the rocket 10 is rotated one full revolution while in launching position, the rocket is cammed forwardly enough so that the hold pin 177 cannot again fall into groove 1775, even though the rocket has not been forwardly moved by the ignited propellant. This insures complete release of the rocket. In Figure 13 the spiraling of groove 175 has been exaggerated for clarity of illustration.

in operation, all spinners are wound and held in wound condition by release discs 156. The rockets 10 are loaded in tubes 125 and forced rearwardly so that the driving keys 171 t into key slots 172 in the sleeves. Hold pins 177 snap into the grooves 175 at their deepest points, and the rockets are thus retained from longitudinal or rotational movement within the launching tube. As the pilot causes control shaft 154 to be rotated, one sleeve 129 will be released to rotate under the urge of the stressed spring 132. This rotation is imparted to the rocket 10 through the driving key 171 and it, too, starts to spin. This first rotational movement actuates the centrifugal switch C hereinbefore described as being a part of the rocket 111, and the rocket propellant 15 is ignited. After one revolution of the rocket 10, the hold pin 177 is cammed completely'out of the groove 175 and the rocket is free to move outwardly under the urge of the propellent charge blast, the latter passing through the hollow body of the sleeve 129 to reach the atmosphere. The rotating sleeve 129 is stopped after slightly less than one revolution by the contact of second abutment member 137 with stop 139. The rocket 10, however, keeps on spinning and leaves the launching tube 125 spin-stabilized on the initial portion vof its Hight.

As it may bc desirable to impart an initial stabilizing spin to rockets substantially larger than the 1.1 inch rocket heretofore described as being spring spun, spinners providing more power than can conveniently be provided by a torsion spring, have been found desirable.

Consequently, other power operated means for providingsuicient energy for imparting the desired initial 12 spin to a rocket are shown in Figures 14 to 19, inclusive. Two modifications of solid fuel operated turbines are there shown, as utilized to impart an initial stabilizing spin to a rocket.

Referring first to Figures 14 to16, inclusive, a turbine casing is mounted in a launching tube 186 on front and rear ball bearings 187 and 189, respectively. The turbine casing 185 is hollow, and a central gas passage 190 is formed by an interior tube 191.

The turbine casing 185 is coupled to a rocket 10 inserted in the launching tube 186 in exactly the same manner as previously described for the spring driven sleeves 129 with the angular driving key 171 in this case extending from the forward end of the turbine casing 185 and cooperating with the key slot 172 in the rear edge of the rocket nozzle 174.

As was the case when the spring driven spinner was used, the rocket is held in position for somewhat less than 360 of rotation by the use of the hold pin 177 riding in the groove 175 of the rocket.

Turbine casing 185 is provided with an end-to=end peripheral slot 192 which, interiorly of the casing 185, is formed into a tangential exhaust nozzle by the insertion of a semi-circular longitudinal partition 194 joining interior tube 191 with the exterior of the casing, as best shown in Figure 15. The outer wall of launching tube 186 is increased in diameter around turbine casing 185 to provide an exhaust gas space 195 which is vented through turbine gas vents 196 leading into an exit nozzle 197 aligned with the gas passage 190 in the turbine casing 185, so that the gases exhausted from the rocket when fired can reach the atmosphere through interior tube 191 and nozzle 197.

The turbine casing 185 is filled with a charge 199 of a conventional solid fuel propellant having a burning time of about .25 second. The charge 199 is fired by a radially extended igniter 21N) embedded in charge 199 adjacent slot 192 and connected to the exterior'of the launching tube 186 through a plug 201 which is readily burnable and breakable on rst rotation on turbine casing 185, for example. This plug 201 also prevents turbine casing rotation prior to ring the turbine.

A plurality of launchers are stacked as shown in Figure 17 to achieve maximum space utilization, so that the increased diameter portions will be in staggered relation. In this case the launchers having the enlarged portions forward may be provided with longer exit nozzles 197 to bring the openings of all nozzles into the same plane.

In operation, each turbine casing 185 is loaded with the rotating charge 199 of solid fuel, and is inserted in launching tube 186 as by removing the exit nozzle 197 at threads 292. The igniter wires are then connected through plug 201 and nozzle 197 is replaced.

A rocket is then loaded into the launching tube and coupled to the turbine casing.

Under pilot control the fuel charge 199 of the particular turbine casing 185 is ignited at the slot 192. As the fuel burns, a tangential blast of gas issues from this slot, rotates the turbine casing at high speed, and thereby rotates the coupled rocket. As hereinbefore described, the rst rocket rotation actuates the centrifugal switch and the rocket charge is ignited; the rocket being released for forward ight after making about a single turn. The time factors of the spinner charge and the rocket propellent charge are adjusted to cause the turbine to impart maximum spin acceleration to the rocket before the coupling is parted.

In case it is not found desirable to increase the diameter of the launching tubes 186, a fuel operated turbine spinner can be used having rear exhaust ports as shown in Figures 18, 19 and 20.

Here, a hollow end driven turbine casing 203 is mounted on lateral bearings 204 in a launching tube 186e of uniform diameter, and is provided on the rear -wall 2.05I with tangential exhaust nozzles 206, igniters 207 being positioned at each nozzle fired through wires passing through breakable plugs 209. The forward end of this type of turbine casing is provided as before described with the driving key 171 to which the rocket is coupled by means of key slot 172 therein.

It will be clearly seen from the preceding description that the present invention provides a satisfactory initial spin to a rocket before it leaves the rocket launcher without necessarily requiring any contribution from energy released from the rocket itself. Complete stability is thus provided as the rocket leaves the launcher and the launching vehicle, permitting, for example, satisfactory rearward launching as shown in Figure l. Furthermore, all necessary precautions are taken to prevent accidental rocket propellant or warhead ignition.

While I have described the invention herein as utilized to provide initial spin for rockets having no inherent means for maintaining spin in flight, it is to be distinctly understood that the invention is equally adapted for use in providing a stabilizing initial spin for rockets that may incorporate means for providing energy for maintaining spin in flight, where it is not desired to utilize such rocket-carried energy to provide all or a major portion of the energy required for an initial stabilizing spin.

While the instant invention has been shown and described herein in what is conceived to be the most practical and preferred embodiments, itis recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein but is to be accorded the full scope of the claims appended hereto.

What is claimed is:

l. A rocket comprising an elongated tubular casing containing an explosive charge and a charge control device including a source of electrical energy therefor, a detonator for said charge, a normally inoperative impact operable switch connected in series with said energy source, an acceleration operable switch, and thermally actuated means operative over a predetermined period of time after launching of said rocket connected in series with said energy source and said acceleration operable switch for rendering said impact operable switch operative said latter means being positioned to close said irnpact operable switch to detonate said warhead after a predetermined additional time interval has elapsed.

2. A rocket comprising an elongated tubular casing containing an explosive charge and a charge control device including a source of electrical energy therefor, a detonator for said charge, a normally inoperative impact operable switch connected in series with said energy source, an acceleration operable switch, and means connected in series with said energy source and said acceleration operable switch for rendering said impact operable switch operative after a predetermined time interval has elapsed after closing of said acceleration operable switch, said latter means being positioned to close said impact operable switch after an additional time interval has elapsed.

3. A rocket comprising an elongated tubular casing containing an explosive charge and a charge control device including a source of electrical energy therefor, a detonator for said charge, a normally inoperative impact operable switch connected in series with said energy source, an acceleration operable swich, heat responsive means movable when heated to render said impact operable switch operative, and heater means adjacent said heat responsive means and connected to said energy source through said acceleration operable switch.

4. A rocket comprising an elongated tubular casing containing an explosive charge and a charge control device therefor, said device including a source of electrical energy, a detonator for said charge, a normally inoperative impact operable switch connected in series with said source, an acceleration operable switch, and means connected in series with said source and said acceleration operable switch for rendering said impact operable switch operable after a predetermined time interval has elapsed after closing of said acceleration operable switch, said latter means operating to close said impact operable switch after a predetermined additional interval of time.

5. A finless rocket to be stabilized by spin applied prior to launching, comprising the combination of an elongated tubular casing containing a forward explosive charge, a rear propellent charge and a charge detonation control device including a battery having first and second electrical cells, propellent charge ignitor means operable only under centrifugal force generated by rocket spin and connected between said rst cell and said ignitor, an acceleration responsive switch effective to be closed upon acceleration of said rocket, a detonator for said explosive charge, an electrical circuit including said second cell and said detonator, an impact operated switch in said circuit, and means for holding said acceleration switch closed after acceleration has ceased until said impact operated switch is operated.

6. A fnless rocket stabilized by a spin applied prior to launching comprising in combination an elongated tubular casing containing a forward explosive charge, a rear propellent charge and a charge detonation control device, said device including a rst electrical cell, a propellent charge ignitor and a switch operable only under centrifugal force generated by rocket spin and connected between said cell and said ignitor, a detonator for said explosive charge, a second electrical cell, an electrical circuit including said detonator and said cell, a switch operable by rocket impact, and means operable by said second cell for connecting said impact switch in said circuit only after a predetermined time has elapsed since initial acceleration of said rocket.

7. In combination with a spin stabilized rocket; an electric cell, an ignitor, circuit means including switch means connecting said cell and ignitor, whereby said ignitor is fired upon closing of said switch means, said switch means including an axial terminal located on the spin axis of the rocket, a first movable switch member having a contact portion disposed on one side of said axial terminal, and another portion disposed substantially diametrically of said contact portion, said other portion being of greater mass than said contact portion, whereby upon spinning of the rocket said switch member is forced outwardly by centrifugal force to cause said contact portion to engage said terminal and thereby close said circuit means to energize said ignitor.

8. Apparatus according to claim 7 wherein said switch means also includes an outer terminal, and a second movable switch member including a contact portion spaced from the axis of the rocket generally diametrically of said other portion and movable outwardly by centrifugal 'force into engagement with said second terminal upon spinning of the rocket, said ignitor being connected between said switch members, and said cell being connected between said terminals, whereby both of said switch members must be brought into contact with their respective terminals in order to complete a tiring circuit to said ignitor.

9. In a rocket having an explosive warhead and a rearwardly disposed propellent charge; the combination of a metal housing mounted rearwardly of said warhead and having a ange disposed transversely of said rocket and forming a wall separating said warhead from said propellent charge; an electric cell mounted within said housing and having a sheath electrically connected to said housing and constituting one terminal of the cell; another terminal of the cell being formed as a rearwardly extending boss; a wall of insulation across said housing adjacent the rear of said cell, said insulation Wall having an opening through which said boss extends; a block of insulation mounted in said housing to the rear of said cell and having a portion thereof spaced from saidinsulation wall to form a `transverse chamber; a .first contact memberincluding aring disposed in said chamber circumjacent said boss, a weight secured to said'ring at one side thereof, and a resilient mounting arm extending from said weight and circumferentially partially around said ring; the other end' of said mounting arm extending into said block and terminating in a first propellent charge tiring terminal; said ring having an inwardly pointed contact located diametrically of said Weight; whereby when the rocket spins said weight is moved outwardly by centrifugal force, thereby tov bring said inwardly pointed contact into engagement with said boss; a second contact member including a second resilient arm extending circumferentially partially around said ring and into said block and terminating in a second propellent charge firing terminal, the other end of said second arm being free and having an outwardly pointed Contact; whereby upon spinning of said rocket said outwardly pointed contact is moved outwardly by centrifugal force to engage said housing, thereby connecting said cell across said propellent charge firing terminals; a propellent charge ignitor connected between said propellent charge tiring terminals; priming material inthe rear end of said housing adjacent said propellent charge iguit'or;said housing having an opening adjacent said priming material and to the rear of said flange; said opening communicating with said propellent charge and being sealed with frangible material; detonator switch mechanism in said housing forwardly of said cell; the forward end of said cell having a forward terminal in the central vportion thereof; said switch mechanism including a longitudinally mounted acceleration pin spaced forwardly of said forward terminal and movable rearwardly into contact with said forward terminal; said pin having an annular shoulder; a first spring circumjacent said pin rearwardly of said shoulder biasing said pin away from said forward terminal; a transverse contact disc at the forward end of said pin having inward radial fingers slidably engaging said pin; a second spring circumjacent said pin and disposed between said shoulder and said contact disc; aL

bimetallic disc mounted transversely of said housing circumjacent said pin and having slots therein dividing said disc into three portions: an inner ring portion, an outer ring portion, and a pair of arcuate arms connecting said inner ring portion and said outer ring portion; said outer ring portion being mounted on said housing; a heater mounted on said bimetallic disc and having the same configuration as said disc, one terminal of said heater being connected to said contact disc; the other terminal of said heater being connected to said housing; said contact disc being mounted on said inner ring portion; a pair of rearwardly extending contact points mounted on said inner ring portion; a resilient intermediate disc mounted transversely of saidvhousing and circumjacent said pin, said intermediate disc having a configuration similar to that of said bimetallic disc; an impact disc mounted transversely of said housing rearwardly of said intermediate disc and having a configuration similar to said bimetallic disc and said intermediate disc; an explosive detonator having one terminal connected to the outer rportion of said impact disc, the other terminal of said detonator being connected to the forward terminal of Asaid cell; said pin being forced rearwardly into engagement with said forward terminal by acceleration of the rocket, thereby to cause iiow of current from said cell through said heater; heating of said bimetallic disc by said heater serving to distort said 'bimetallic disc and move said inner ring portion rearwardly to press said points into engagement with said intermediate disc and to move said second spring rearwardly and thereby overcome said first spring to maintain said pin in engagement with said forward terminal; continued heating of said bimetallic disc serving eventually to cause said points to press said intermediate disc into engagement with said impact disc; said impact disc being forced forwardly, when the rocket strikes an object, to engage said intermediate disc and complete a circuit from said cell through said detonator; explosive primer in said housing adjacent said detonator; said housing having anV opening adjacent said primer and forwardly of said flange; said opening being sealed with a frangible material; whereby upon completion of a circuit from said cell through said detonator said primer is ignited and fractures said frangible material to ignite the explosive warhead in the forward part of the rocket.

l0. ln a rocket having propellent charge in the aft part thereof, the combination of a metal housing having a flange disposed transversely of the rocket and forming the forward wall of a propellent section; an electric cell mounted within said housing having a sheath electrically connected to said housing and constituting one terminal of the cell, another terminal of the cell being formed as a rearwardly extending boss; a wall of insulation across said housing adjacent the rear of said cell, said insulation wall having an opening through which said boss extends; a block of insulation mounted in said housing to the rear of said cell and having a portion thereof spaced from said insulation wall to form a transverse chamber; a first switch member including a ring disposed in said chamber vcircumjacent said boss, a weight secured to said ring at one side thereof, and a resilient mounting arm extending from said weight and circumferentially partially around said ring; the other end of said mounting arrnnextending into said block and terminating in a first propellent charge firing terminal; said ring having an inwardly pointed contact located diametrically of said weight; whereby when the rocket spins said weight is moved outwardly by centrifugal force, thereby to bring said inwardly pointed contact into engagement with said boss; a second switch member including a second resilient arm extending circumferentially partially around said ring and into said block and terminating in a second propellent charge tiring terminal, the other end of said second arm being free and having an outwardly pointed contact, whereby upon spinning of said rocket said outwardly pointed contact is moved outwardly by centrifugal force to engage said housing, thereby connecting said cell across said propellent charge tiring terminals; a propellent charge ignitor connected between said propellent charge tiring terminals; priming material in the rearrend of said housing adjacent said propellent charge ignitor; said housing having an opening adjacent said priming material and to the rear of said flange, said opening communicating with said propellent charge and being sealed with frangible material.

11. In a rocket having an explosive warhead in the' forward part thereof, the combination of a metal housing disposed in the rear portion of the warhead and forming the rear wall of the warhead; an electric cell mounted rearwardly in said housing having a sheath electrically connected to said housing and constituting the terminal of said cell, another electric cell mounted forwardly in said housing and having a forward terminal in the central portion thereof; detonator switch mechanism disposed forwardly of said cell and including a longitudinally mounted acceleration pin spaced forwardly of said forward terminal and movable rearwardly into contact with said forward terminal; said pin having an annular shoulder; a first spring circumjacent said pin rearwardly 4of said shoulder biasing saidpin away from said forward terminal; a transverse contact disc at the forward end of said pin having inward radial fingers slidably engaging said pin; a second spring circumjacent said-pin and disposed between said shoulder and said contact disc, a bimetallic disc mounted transversely of said housing circumjacent said pin and having slots therein dividing said discinto three portions; an inner ring portion,V anouter ring portion, and a pair ofy arcuate arms connecting said inner ring'portion and said outer ring portion; said outer ring portion` being mounted on said housing, aheater mounted onrsaid bimetallic disc and having the same con figuration as said disc; one terminal of said heater being connected to said contact disc; the other terminal or" said heater being connected to said housing; said contact disc being mounted on said inner ring portion, a pairof rearwardly extending contact points mounted on said inner ring portion; a resilient intermediate disc mounted transversely of said housing and circumjecent said pin, said intermediate disc having a configuration similar to that of said bimetallic disc; an impact disc mounted transversely of said housing rearwardly of said intermediate disc and having a configuration similar to said bimetallic disc and said intermediate disc; an explosive detonator having one terminal connected to the outer portion of said impact disc, the other terminal of said detonator being connected to the forward terminal of said cell; said pin being forced rearwardly into engagement with said forward terminal by acceleration of the rocket, thereby to cause flow of current from said cell through said heater; heating ofv said bimetallic disc by said heater serving to distort said bimetallic disc and move said inner ring portion rearwardly to press said points into engagement with said intermediate disc and to move said second spring rearwardly and thereby overcome said first spring to maintain said pin in engagement with said forward terminal; continued heating of said bimetallic disc serving eventually to cause said points to press said intermediate disc into engagement said mpact disc; said impact disc being forced forwardly, when the rocket strikes an object, to engage said intermediate disc and complete a circuit from said cell through said detonator; explosive primer in said housing adjacent said detonator; said housing having an opening adjacent said primer and forwardly of said ange; said opening being sealed with a frangible material; whereby upon completion of a circuit from said cell through said detonator said primer is ignited and fractures said frangible material to ignite the explosive warhead in the forward part of the rocket.

l2. Warhead detonation mechanism comprising in combination, an electrically fired detonator, an electric cell, circuit means including detonator switch means effective to tire said detonator to explode said warhead, said detonator switch means including impact switch means eifective to close said circuit means upon deceleration of said warhead and acceleration switch means effective to be closed upon acceleration of said warhead, thermal switch means electrically connected in series with said impact switch means, and heater means for heating said thermal switch -means and connected to be energized by said cell upon closing of said acceleration switch means.

13. Warhead detonation mechanism comprising in combination, an electrically fired detonator, an electric cell, circuit means including detonator switch means effective to fire said detonator to explode said warhead, said detonator switch means including impact switch means eiective to close said circuit means upon deceleration of said warhead and acceleration switch means eiective to be closed upon acceleration of said warhead, thermal switch means electrically connected in series with said impact switch means, heater means for heating said thermal switch means and connected to be energized by said cell upon closing of said acceleration switch means, and safety means interposed between said impact switch means and said thermal switch means to prevent closing of said detonator switch means until said thermal switch means has been moved into contact with saidsafety means solely by heat from said heater means.

14. In a missile having an explosive warhead; the combination of an electrically fired warhead detonator having two connections, an electric cell having a positive terminal and .a negative terminal, one connection of said detonator being connected to said negative terminal, a normally open impact operable switch, the other said detonator connection being connected to said impact switch, means defining a circuit connected on one end thereof to said positive terminal, a normally open acceleration responsive switch in said circuit, said acceleration responsive switch being movable to contact said negative terminal when said missile is launched, and thermal means movable over a predetermined period of time to make electrical contact with said impact operable switch to completely close said circuit between said positive terminal and said detonator to explode said warhead.

l5. In a missile having an explosive warhead; the combination of an electrically tired warhead detonator having two connections, an electric cell having a positive terminal and a negative terminal, one connection of said detonator being connected to said negative terminal, a normally open impact operable switch, the other said detonator connection being connected to said impact switch, means dening a circuit connected on one end thereof to said positive Iterminal, a normally open acceleration responsive switch in said circuit, said acceleration responsive switch being movable to contact said negative terminal when said missile is launched, and thermally expandible means associated with said acceleration switch and movable over a predetermined period of time to make electrical contact with said impact operable switch to completely close said circuit between said positive terminal and said detonator to explode said warhead.

16. In a missile having an explosive warhead; the combination of an electrically tired warhead detonator having two connections, an electric cell having a positive and negative terminal, one connection of said detonator being connected .to said negative terminal, means defining a normally open circuit connecting the other connection of said detonator `to said positive terminal, a normally open impact operable switch in said circuit, a normally open acceleration responsive switch in circuit and movable `to make connection with said negative terminal to arm said warhead when said missile is launched, thermally movaible means associated with said acceleration responsive switch and operative within a predetermined period of time after said acceleration is connected to said negative terminal to make electrical contact with said impact operable switch and completely close said circuit to detonate said warhead.

l7. In a missile having an explosive warhead; the combination of an electrically tired warhead detonator having two connections, an electric cell having a positive and negative terminal, one connection of said detonator being connected to said negative terminal, means defining a normally open circuit connecting the other connection of said detonator to said positive terminal, a normallyl open impact operable switch in said circuit, a normally open acceleration responsive switch in said circuit and movable to contact said negative terminal to arm said warhead when said missile is launched, a heat responsive conductor associated with said acceleration responsive switch and heated upon acceleration of said missile, said 'heat responsive conductor being movable when heated to electrically contact said impact operable switch and completely close said circuit .to detonate said warhead within a predetermined period of timeafter said acceleration responsive switch contacts said negative terminal.

References Cited in the file of this patent UNITED STATES PATENTS 2,403,567 Wales July 9, 1946 2,404,179 King July 16, 1946 FOREIGN PATENTS 376,987 Italy Dec. 4, 1939 436,932 Italy June 18, 1948 

